midi track keyboard triggering multiple items

I have noticed that while using Toontrack Superior Drummer 2, if I play a midi drum track it works fine. If I hit the corresponding key that was used to trigger the hi-hats or kick, or whatever using the mouse, it triggers multiple drums (bongos, snare, symbols, etc.) inside that same VST drum kit.

I have not yet tried to diagnose this if is something odd I’ve done, or unique to superior drummer. This doe not happen consistently either. I’m wondering if anybody else has had this problem in Cubase Pro 8?